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Voice of America to Test Digital Transmissions this Weekend

The Voice of America Radiogram show, hosted by Kim Andrew Elliot, KD9XB, will be testing a variety of digital modes on March 16 and 17.

The data transmissions can be decoded by anyone with an AM shortwave receiver using any of the popular sound-card-based programs such as Fldigi, Ham Radio Deluxe, MixW, MultiPSK, DigiPan (for BPSK31, BPSK63 and QPSK31 only), CocoaModem (for Macs) and others.

Each test will last one minute, unless otherwise specified, on the following modes at the audio frequencies indicated. During some tests as many as four modes will be used simultaneously . . .

BPSK31 at 2000 Hz

QPSK31 at 1000 Hz, BPSK31 at 2000 Hz

QPSK31 at 1000 Hz, PSK63F at 1500 Hz, BPSK31 at 2000 Hz

QPSK63 on 1000 Hz, PSKR125 at 1500 Hz, BPSK63 at 2000 Hz

QPSK125 at 1000 Hz, PSKR250 at 1500 Hz, BPSK63 at 2000 Hz

QPSK250 at 800 Hz, PSKR500 at 1500 Hz, BPSK250 at 2200 Hz

QPSK500 at 800 Hz, PSKR1000 at 1500 Hz, BPSK500 at 2200 Hz

PSKR500 at 1000 Hz, PSK63F at 1500 Hz, PSKR125 at 2000 Hz, and PSKR250 at 2500 Hz (5 minutes, 40 seconds total). The latter portions of the PSKR250 and 500 transmissions are formatted for Flmsg, a function within the Fldigi software suite. (In Fldigi, go to Configure > Misc > NBEMS > under “Reception of flmsg files.” Click Open with flmsg and Open in browser and select the desired location of the flmsg.exe file.)

MFSK32 image on 1500 Hz (54 seconds)

The 30-minute Radiogram program is scheduled to air . . .

Saturday 1600 UTC at 17860 kHz

Sunday 0230 UTC at 5745 kHz

Sunday 1300 UTC at 6095 kHz

Sunday 1930 UTC at 15670 kHz

... from the IBB Edward R. Murrow Transmitting Station in North Carolina.

According to Elliot, future VOA Radiogram programs will transmit only one mode at a time. “This will ensure the highest possible signal-to-noise ratio and the best possible chances for a successful decode. These broadcasts are an experiment. We will try different modes in different programs to see which work best via AM analog shortwave broadcast transmitters.”